Fabrication of Condenser Microphones on Silicon On Insulator Wafer
SHINSUKE HISHINUMANAOKI KIMORIYUICHIRO KUMAIKOUKI OKUTETSUYA TAKAHASHIDAIKI IROKAWAEMIKO SUGIZAKINAOKI WATANABETSUYOSHI IKEHARARYUTARO MAEDAYASUSHIRO NISHIOKA
摘要：A silicon condenser microphone on an SOI （silicon on insulator） substrate using only one photo mask was fabricated. This microphone consists of a diaphragm with the thickness of 20 m and the diameter of 2 mm, a SiO 2 insulative spacer （4- m-thick buried oxide）, and a 450- m-thick silicon back plate with the meshed structures having extremely small （60 m） hexagonal shaped acoustic holes. The gap between the 20- m-thick silicon diaphragm and the back plate is 4 m, which is determined by the thickness of the buried oxide in the SOI wafer. This microphone was confirmed to function as a static pressure sensor. The SOI microphone was also connected to an amplifier circuit, and exposed to the sound pressure of 110 dB at the frequency of 1 kHz. The microphone clearly responded to the input sound, and the output ac voltage of approximately 40 μ V was detected.
The 1st International Congress on Advanced Materials 2011